Antenna tuning question

I run a Cobra 29 LTD with a Palomar Elite 250. I just bought a Wilson 5000 Magnetic mount antenna and am trying to install it. When I check my SWRs with the Palomar turned off, I get a reading of 2.5 but when I turn the Palomar on, the reading drops to 1.8. Is that something to be concerned about and something that I should have a CB shop check out???

 

Are u using an external meter? If so Where are you checking? At the radio? At the amp?

 

The meter is built in to the radio.

 

Get an external meter or have a cb shop do it. In radio meters are highly inaccurate. You can blow an amp up quick with high swr. Most want no more then 1.3.

 

You are checking the SWR from the radio to the AMP not the antenna.

When you switch the AMP off you get a reading through the AMP to the antenna which may or may not be a true reading.

I would recommend a good quality external SWR meter. And install it between the antenna and the AMP.

leon

 

I've always been told to check swr at the start of the coax (at the radio). What is the reason for checking between amp and the antenna? If you do that you are missing the jumper coax and any problems from the radio to amp.

 

I bought an external meter and installed it between the Amp and Antenna. Here are my readings:

With the amp turned off, I get an SWR reading of 1.2 on 40, 1, and 19.

With the amp turned on, I get an SWR reading of 2.5 on all 3 channels and my Palomar Elite 250 is only putting out about 80 watts. What gives???

 

Stop and think for a moment You are trying to see the reflected wave from the antenna. Since the AMP presents a load to test the SWR the meter has to be connect between the AMP and the antenna.

If you connect it between the radio and the AMP then you are checking the SWR on the input on the AMP. You no idea what is happening at the antenna.

leon

 

Something doesn't seem right with your readings. I haven't see readings that are flat a crossed the band. Normally, it should be lowest on chan 19 and rise at each end.

Are you resetting the meter each time you take a reading?

leon

 

Yes but I can't figure out what is causing the jump to 2.5.